Currently, the main argument for not permanently disabling Extension:Oversight is that Oversight can do something that RevisionDelete can not, namely, hide all existence of an edit. For example, suppose an editor signs a talk page when logged out, then logs in and resigns, and asks for oversight of the logged-out edit. Oversight removes the edit completely, making it look like the editor's only edit was the logged in one. RevDel can be used to hide the IP, or even fully delete the edit, but even when fully deleted and suppressed, there is a placeholder that indicates that "something" was removed.
Therefore, add an option to RevisionDelete to "hide the placeholder" from editors who do not have oversight permission. This will have the same net effect and appearance to most users as oversight, solving the objections of some people to turning oversight off completely. However, it will be reviewable and reversible.